Embodiments of the inventive concept relate to an image sensor, and more particularly, to a pixel including a back deep trench isolation (DTI) and a vertical transfer gate, an image sensor including the pixel, and a portable electronic device including the image sensor.
Image sensors (or image sensor chips) are semiconductor devices that convert an optical image into an electrical signal. Image sensors can be divided into charge-coupled device (CCD) image sensors and complementary metal-oxide-semiconductor (CMOS) image sensors. CCD image sensors include a high-voltage analog circuit. CMOS image sensors can be manufactured at lower cost than CCD image sensors, and are smaller than CCD image sensors and thus consume less power than CCD image sensors.
Higher performance in CMOS image sensors has led to them being widely used in electronic appliances as well as in smart phones and digital cameras. A CMOS image sensor includes a photoelectric conversion element that generates charges from incident light and a processing circuit that processes electronic signals corresponding to the charges. To increase the resolution of an image that can be produced using a CMOS image sensor, it is necessary to increase the number of pixels in a pixel array of the CMOS image sensor. The greater the number of pixels becomes, the smaller the pixels must be for a given area of the pixel array. Accordingly, increasing the resolution that can be provided by an imaging device employing a CMOS image sensor presents a problem of increasing the likelihood that interference, such as crosstalk, may occur between pixels of the sensor.